1902] CURRENT LITERATURE , 153 



The latter show rings of growth. The young plants have a single blade, as 

 is true of all keljjs, the lateral pinnae developing as outgrowths from the 

 stipe below the blade in a manner similar to Alaria.— B. M. Davis. 



Habitual polyembryony has been observed by Hegclmaier" in Euphor- 

 bia dHlcis]^.zi\. In about two-thirds of the half ripe seeds there is more than 

 one embryo, the number ranging from two to nine. In the ripe seed the num- 

 ber is smaller, usually two or three, and one of these considerably larger than 

 the others. The embryo which develops from the egg is the only one which 

 has a suspensor, and is also the one which becomes the largest embryo in the 

 ripe seed. Of the other embryos, some come from synergids and some from 

 cells of the nucellus. A large per cent, of the polyembryonic seeds are not 

 capable of germinating on account of the disorganization of the embryo. 



Charles J. Chamberlain. 



The timothy rust, which has generally been referred to Puccinia 

 graminis Pers., was set apart by Eriksson as the result of cultures in 1891-93, 

 under the name Puccinia Phlei-pratcnsis E. & H. In a recent article'^'' the 

 work of this period is critically examined, and many additional cultures, made 

 during 1894-T900, are reported. The conclusion is reached that the species 

 is autonomous, that it occurs on Phlettm prate7tse and Festuca elatior, and 

 that it may be transferred sparingly by cultures to Phleu??i MichcHi, Avcna 

 sativa, and Secale cereale, but not to Pklcum aspcrum, and other grasses. 

 Neither will it infect the barberry, and it appears to have lost the power to 

 form aecidia. It is doubtful if this species occurs in America. It has been 

 reported under Xht n2.mt P, graminis oncG^ upon Festuca elatior (Vermont, 

 1898), but examination of the original material reveals an error ; and once 

 upon /'/^/^////^^ra/^-/^^^ (Wisconsin, 1884), which has not been re-examined. 



J. C. Arthur. 



Hassexkamp=^3 describes the development of the cystocarp in two red 

 a^&ae, Thurefella Shottsboei and Chylocladia kaliformis, and his results sup- 

 port Oltmanns' theory of the relation which the auxiliary cells bear to the 

 fertilized carpogonium. He finds that when the carpogonium fuses with an 

 auxiliary cell, the respective nuclei remain quite apart, so that the union con- 

 cerns the cytoplasm alone. The sporogenous nuclei (sporophytic) are then 

 active in developing the fertile portions of the cystocarp with the spores. 



91 



Hegelmaier, F., Ueber einen neuen Fall von habitueller Polyembryonie. 

 Ber. Deutsch. Bot. Gesells. ig : 488-499. 1901. 



Eriksson, Jakob, 1st der Timotheengrasrost eine selbstandige Rostart oder 

 nicht ? Ofv. K. Vet.-Akad. Forh. 1902 : 1S9-19S. 



Hassenkamp, a., Ueber die Entwickehing der Cystocarpien bei einigen Flori- 



33 



deen. Bot. Zeit. 60:65-86. //. 2, figs, 12. 1902. 



f 



